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传统的AVO正演只考虑了单一界面的反射系数对地震波波场振幅的影响,忽略了地震波在介质中传播的各种传播效应。通过引入地震波在介质中传播的几何扩散、吸收衰减以及透射损失等传播效应,提出了基于射线理论的水平层状介质多波保幅AVO正演方法。推导了水平层状介质多波几何扩散校正公式,来描述多波在介质中传播的几何扩散效应。通过直接引入复旅行时,而无需借助复速度,建立了复旅行时与品质因子的关系,来描述粘弹介质的吸收衰减。直接求解Zoeppritz方程计算多波的透射系数,用于描述多波在介质中传播时的透射损失。数值计算表明,几何扩散、吸收衰减以及透射损失对多波振幅的影响是随偏移距变化而变化的,多波保幅AVO正演需要考虑波传播效应对反射波振幅的改造。
The traditional AVO forward only considers the influence of the reflection coefficient of a single interface on the amplitude of the seismic wave field, ignoring the various propagation effects of the seismic wave propagating in the medium. By introducing propagation effects such as geometric diffusion, absorption attenuation and transmission loss of seismic waves propagating in medium, a multi-wave amplitude preserving AVO forward method based on ray theory is proposed. The multi-wave geometry diffusion correction formula for horizontal layered media is derived to describe the geometric diffusion effect of multi-wave propagation in the media. Through the direct introduction of complex travel without the need of complex velocity, the relationship between complex travel and quality factor is established to describe the absorption attenuation of viscoelastic media. The Zoeppritz equation is solved directly to calculate the multi-wave transmission coefficient, which is used to describe the transmission loss of multiwave propagation in the medium. The numerical results show that the influence of geometric diffusion, absorption attenuation and transmission loss on the amplitude of multi-wave varies with the offset, and multi-wave amplitude preserving AVO forward needs to consider the effect of wave propagation on the amplitude of the reflected wave.